1. Field of the Invention
This invention generally relates to a bicycle pedal. More specifically, the present invention relates to a clipless or step-in bicycle pedal having a tread cage.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle as well as the frame of the bicycle. One component that has been extensively redesigned is the bicycle pedal.
In recent years, bicycle pedals have been designed for specific purposes such as for pleasure, off road biking, road racing, etc. One particular type of bicycle pedal, which is gaining more popularity, is the step-in or clipless pedal, which releasably engages a cleat secured to the sole of a cyclist""s shoe. The clipless pedal has a pedal spindle that can be mounted on the crank of a bicycle, a pedal body that is rotatably supported on this pedal spindle, and a cleat engagement mechanism. In an off road bicycle pedal a cleat engagement mechanism is formed on both sides of the pedal body for engaging a cleat. Road racing pedals, on the other hand, typically only has a cleat engagement mechanism on one side of the pedal body. In either case, in this type of bicycle pedal, the rider steps onto the pedal and the cleat engagement mechanism automatically grips on to the cleat secured to the bottom of the cyclist""s shoe.
When attaching the cyclist""s shoe to the step-in or clipless pedal via the cleat, the cyclist moves the shoe obliquely downwardly and forwardly relative to the pedal body such that the front end of the cleat engages a front hook or clamping member of the pedal body. Once the front end of the cleat is engaged with the front hook of the pedal body, the cyclist places the rear end of the cleat in contact with a guide portion of the rear hook or clamping member of the pedal body. In this position, the cyclist presses the shoe downwardly against the pedal to cause the rear hook or clamping member to initially pivot rearwardly against the force of a spring to move the rear hook or clamping member to a cleat releasing position. The rear end of the cleat then enters a position opposite a back face of the rear hook or clamping member. Then, the rear hook or clamping member returns under the force of a biasing member or spring so that the rear hook or clamping member engages the rear end of the cleat. This engagement fixes the cyclist""s shoe to the pedal via the cleat.
When releasing the shoe from the pedal, the cyclist will typically turn the shoe about an axis perpendicular or approximately perpendicular to the tread of the pedal, using the front end of the cleat as a pivoting point. As a result of this pivoting action, the rear hook or clamping member is pivoted rearwardly against the force of the spring to a cleat releasing position to release the shoe.
With this type of step-in or clipless pedal, the shoe and the pedal are in a state of constant engagement when the cleat clamping is engaged in the cleat clamping members, so the pedaling force can be transmitted efficiently to the pedals. As a result, step-in or clipless pedals are widely employed on racing bicycles used in road racing and mountain bike racing.
One problem with most step-in or clipless pedals is that they are quite small such that only small portions of the pedal body engage the rider""s shoe. Specifically, the pedal body has a tread surface located on both sides of the cleat engagement mechanism. This tread surface has only a small surface area because the pedal body is typically made as small as possible so that it will be lightweight. Thus, it is often difficult to apply a pedaling force when the cleat is not engaged.
Furthermore, with off-road racing the foot must be repeatedly taken off the pedal during cornering and replaced on the pedal after the corner has been exited. Unfortunately, since the racing is performed on unpaved roads, mud clings to the pedals and tends to clog the clamping members. Once the clamping members become clogged with mud, the cleat cannot be engaged in the clamping members, and the shoe cannot be attached to the pedal. Moreover, the mud often clogs the biasing mechanism such that the clamping members may not operate properly.
When a cleat cannot be engaged with the cleat engagement members because of mud clogging, or when the feet are frequently removed from the pedals, the rider must often step on the pedal without the cleat being engaged in the cleat engagement members. However, since the pedal body of the above-mentioned conventional clipless pedals has as small a volume as possible and has only a small tread surface, the foot would slip around to the left and right when the cleat was not engaged with the cleat engagement members. As a result, the pedaling force is not transmitted efficiently to the pedals, and the speed of the bicycle drops. Lower speed is a critical problem for a racer. Accordingly, when it is expected that the pedals will become clogged with mud or the shoes will be taken off and replaced on the pedals frequently in this type of off-road race, more and more riders are using ordinary double-sided pedals rather than clipless pedals. Such pedals have no cleat engagement members, but they provide a good grip to the shoes. However, in either case, the cyclist does not have an optimum apparatus for pedaling the bicycle.
For a clipless pedal to be usable in such muddy situations, it must be possible for the rider to firmly step on the pedal even when the cleat is not engaged with the cleat engagement members. One possible means for achieving this could be to provide a wide tread cage on the pedal around the outside of the cleat engagement members so that more tread surface can come into contact with the shoe sole. However, if a wide tread cage is provided around the outside of the cleat engagement members, then the tread cage will interfere with the shoe sole and get in the way when the cleat is being engaged with the cleat engagement members. This may result in difficulties in engagement of the cleat with the pedal. Consequently, when the shoe is inserted from a direction other than the engagement direction, it will be difficult to reengage the cleat with the cleat engagement members quickly even if there is no mud clogging or the like.
Accordingly, step-in pedals have been designed with tread cages that have a small range of pivotal movement between the tread cage and the pedal body. In such an arrangement, tread cage is biased relative to the pedal body by a torsion spring. These bicycle pedals are provided with front and rear cleat engaging members that are coupled to the pedal for engaging corresponding front and rear portions of the cleat. A tread cage having a relatively wide tread surface is coupled to the pedal for movement relative to at least one of the front cleat engaging members or rear cleat engaging members. The wide tread surface provides stable contact between the cycling shoe and the pedal when the cleat is disengaged from the cleat engaging members. The movable tread cage allows the tread surface to move away from the cleat engaging members so as not to interfere when the cyclist is in the process of engaging the cleat with the cleat engaging members. The torsion spring is coupled between the tread cage and the pedal body to hold the tread cage in the appropriate position. While these prior art step-in pedals work very well, the torsion spring can fail over an extended period of time. Moreover, the torsion spring increases the costs of manufacturing the pedal.
In these prior pedals, the tread cage is typically constructed of a hard rigid material such as a metal alloy or a hard plastic material. Since pedals with tread cages are typically used in off road riding or down hill racing, the pedal and tread cage are often subjected to rough conditions, e.g., being hit by rocks and the like. Tread cages that are constructed of hard rigid materials can often be damaged. Moreover, the hard rigid materials used in prior art tread caged do not provide optimum contact with the sole of the bicycle shoe.
In view of the above, there exists a need for a bicycle pedal which overcomes the above mentioned problems in the prior art. In view of the above, it is apparent that there exists a need for a step-in bicycle pedal which is relatively durable and relatively inexpensive to manufacture. This invention addresses these needs in the art, along with other needs, which will become apparent to those skilled in the art once given this disclosure.
One object of the present invention is to provide a step-in bicycle pedal with a tread cage that is constructed of a shock absorbing material.
Another object of the present invention is to provide a step-in bicycle pedal with a tread cage that has a relatively durable tread cage.
Another object of the present invention is to provide a step-in bicycle pedal with a tread cage that provides better contact between the tread cage and the sole of the shoe.
Another object of the present invention is to provide a step-in bicycle pedal with a tread cage that does not require a coiled spring between the tread cage and the pedal body.
Another object of the present invention is to provide a step-in bicycle pedal with a tread cage in which the connection between the tread cage and the pedal body is less prone to malfunction.
Another object of the present invention is to provide a step-in bicycle pedal with a tread cage that is relatively inexpensive to manufacture.
In the present invention, a pedaling force can be efficiently transmitted to the bicycle pedal even if the cleat is not engaged, but the cleat also can be engaged with ease.
The foregoing objects of the present invention can be attained by providing a bicycle pedal for attaching a shoe thereto via a cleat. The bicycle pedal of the present invention basically has a pedal spindle, a pedal body and a tread cage. The pedal spindle has a center longitudinal axis of rotation. The pedal body is rotatably coupled to the pedal spindle. The pedal body has a first cleat engagement mechanism coupled to a first side of the pedal body to fixedly couple the cleat within a first cleat receiving area formed by the first cleat engagement mechanism. The tread cage is non-rotatably coupled to the pedal body to rotate therewith about the pedal spindle. The tread cage has a first tread surface located on the first side of the pedal body. The tread cage is at least partially constructed of a resilient material to allow deflection of the tread cage relative to the pedal body.
In one embodiment of the present invention, the bicycle pedal for attachment to a cleat fixed to a bicycle shoe is provided with front and rear cleat engaging members that are coupled to the pedal for engaging corresponding front and rear portions of the cleat. A tread cage having a relatively wide tread surface is coupled to the pedal for movement relative to at least one of the front cleat engaging members or rear cleat engaging members. The wide tread surface provides stable contact between the cycling shoe and the pedal when the cleat is disengaged from the cleat engaging members. The deformable tread cage allows the tread surface to move away from the cleat engaging members allowing the cyclist to engage the cleat with the cleat engaging members.
In one embodiment of the present invention, the tread cage of the bicycle pedal must be deformed for the cleat to engage the cleat engagement mechanism of the pedal body. Preferably, the tread surface is at least partially located to overlie a portion of the first cleat receiving area of the first cleat engagement mechanism as viewed in a direction parallel to the center longitudinal axis of rotation. Thus, the tread cage must be elastically deformed for complete engagement of the cleat with the first cleat engagement mechanism, when the cleat is coupled to the bicycle shoe.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.